About a year ago I installed about 18 Seaway vinyl replacement windows. I removed the old storm windows, and used a piece of L-shaped matching flashing to cover the blind stop and then caulked between the old wrapping to the new piece and then, naturally, from the blind stop to the window. I used a colored QSI Quad caulk which everyone seems to rave about.

So on a few windows (3 in particular that get baked in the sun) I immediately had problems with the caulk bubbling/pushing out on the bead between the window and blind stop (PICTURES ATTACHED). I would put it on, it would look great for a couple hours, then within a day or two it would look terrible. After about a year, I have noticed that a number of windows have this same problem (the windows with the issues seem to be ones that sit in direct sunlight for half a day). The worst two windows sit in an unheated garage and the caulk looks absolutely horrific after a year (this is in upstate ny). The odd thing is that on all these windows, where I caulked the transition from the old flashing to the new L-flashing to cover the blind stop, this still looks great. It is just the caulk from where the blind stop meets the vinyl window that is an issue.

Any thoughts on how to fix this or why it is an issue? I have attempted to recaulk several of these problem areas and it always returns. Is there another type of caulk which has this color I should be using? I have never had this problem with the plain cheap white caulk from the home centers.

Strange. Maybe something is moving around, or perhaps there was some silicone that was caulked over or something? In thousands upon thousands of windows caulked I've never seen quad do that on its own... Maybe someone else will chime in..

In my experience there's only one thing I've seen in common with anything bubbling or peeling. MOISTURE!! When paint peels or caulk starts doing that crazy thing it does.....its moisture behind the product. Sometimes water penetrates after the new window is installed. I've had this happen to a couple of my installers and myself. It could also be dirty existing paint. If there's any substance on the old paint it can cause the caulk to seperate. The only way I've fixed this is by removing all the caulking and palm sanding the wood with a 60 grit paper. The more you remove the better chance of a good adhesion. I'll even bust out my jobsite 1970's model hair dryer to dry all the wood down. I'd recommend a nice sunny day with temps in the 70's to 80's. If it's cold out you could trap moisture behind the caulk or it doesn't dry properly. The water then freezes and pop goes the caulking.
Another issue could be you're finish painting the caulk before it's completely dry. More moisture trapping.
Hope this helps you find a conclusion. Good Luck!!!